Can't build with VS2017

[Stretto]

Trying to build, I get the errors:

B:\Temp\luaffi-master\msvc\stdbool.h(36): error C2632: 'char' followed by 'bool' is illegal
B:\Temp\luaffi-master\msvc\stdbool.h(36): warning C4091: 'typedef ': ignored on left of 'unsigned char' when no variable is declared
ctype.c
B:\Temp\luaffi-master\msvc\stdbool.h(36): error C2632: 'char' followed by 'bool' is illegal
B:\Temp\luaffi-master\msvc\stdbool.h(36): warning C4091: 'typedef ': ignored on left of 'unsigned char' when no variable is declared
ffi.c
B:\Temp\luaffi-master\msvc\stdbool.h(36): error C2632: 'char' followed by 'bool' is illegal
B:\Temp\luaffi-master\msvc\stdbool.h(36): warning C4091: 'typedef ': ignored on left of 'unsigned char' when no variable is declared
parser.c
B:\Temp\luaffi-master\msvc\stdbool.h(36): error C2632: 'char' followed by 'bool' is illegal
B:\Temp\luaffi-master\msvc\stdbool.h(36): warning C4091: 'typedef ': ignored on left of 'unsigned char' when no variable is declared

If I hack stdbool, I seem to get the same error but with complex.

Best I can tell, it has to do with something similar with

https://stackoverflow.com/questions/15191127/changes-meaning-from-typedef
?